func (e *Engine) CreateIterator(opt influxql.IteratorOptions) (influxql.Iterator, error) {
if call, ok := opt.Expr.(*influxql.Call); ok {
refOpt := opt
refOpt.Expr = call.Args[0].(*influxql.VarRef)
aggregate := true
if opt.Interval.IsZero() {
switch call.Name {
case "first":
aggregate = false
refOpt.Limit = 1
refOpt.Ascending = true
case "last":
aggregate = false
refOpt.Limit = 1
refOpt.Ascending = false
}
}
inputs, err := e.createVarRefIterator(refOpt, aggregate)
if err != nil {
return nil, err
} else if len(inputs) == 0 {
return nil, nil
}
// Wrap each series in a call iterator.
for i, input := range inputs {
if opt.InterruptCh != nil {
input = influxql.NewInterruptIterator(input, opt.InterruptCh)
}
itr, err := influxql.NewCallIterator(input, opt)
if err != nil {
return nil, err
}
inputs[i] = itr
}
return influxql.NewParallelMergeIterator(inputs, opt, runtime.GOMAXPROCS(0)), nil
}
itrs, err := e.createVarRefIterator(opt, false)
if err != nil {
return nil, err
}
itr := influxql.NewSortedMergeIterator(itrs, opt)
if itr != nil && opt.InterruptCh != nil {
itr = influxql.NewInterruptIterator(itr, opt.InterruptCh)
}
return itr, nil
}
func (e *Engine) CreateIterator(opt influxql.IteratorOptions) (influxql.Iterator, error) {
if call, ok := opt.Expr.(*influxql.Call); ok {
refOpt := opt
refOpt.Expr = call.Args[0].(*influxql.VarRef)
inputs, err := e.createVarRefIterator(refOpt)
if err != nil {
return nil, err
} else if len(inputs) == 0 {
return nil, nil
}
// Wrap each series in a call iterator.
for i, input := range inputs {
if opt.InterruptCh != nil {
input = influxql.NewInterruptIterator(input, opt.InterruptCh)
}
itr, err := influxql.NewCallIterator(input, opt)
if err != nil {
return nil, err
}
inputs[i] = itr
}
return influxql.NewParallelMergeIterator(inputs, opt, runtime.GOMAXPROCS(0)), nil
}
itrs, err := e.createVarRefIterator(opt)
if err != nil {
return nil, err
}
itr := influxql.NewSortedMergeIterator(itrs, opt)
if itr != nil && opt.InterruptCh != nil {
itr = influxql.NewInterruptIterator(itr, opt.InterruptCh)
}
return itr, nil
}